up-yours.com - Here we go again

I thought I'd made this clear, but apparently not. I got an e-mail earlier, from a RoadRunner IP (residential US ISP), using an @up-yours.com address.There's two problems here however;1. It's an invalid address, so can't reply2. The e-mail houses a childish threat, without actually telling me what I did to deserve it*********************************************************************General*****